Endurance athletes face a constant challenge: how to fuel long efforts without upsetting your stomach. Two brands have emerged as favorites in the running and cycling communities—Tailwind Nutrition and Skratch Labs. Both promise clean ingredients and science-backed formulas, but they take distinctly different approaches to keeping you hydrated and energized.
Tailwind positions itself as an all-in-one solution, delivering calories, electrolytes, and hydration in a single bottle. Skratch, on the other hand, champions real-food ingredients and advocates for separating hydration from fueling. Understanding these philosophies—and the nutrition behind them—can help you choose the right product for your training needs.
Tailwind: The All-in-One Fuel Strategy
Tailwind Nutrition built its reputation on simplicity. Their flagship product, Endurance Fuel, is designed to be your only fuel source during activity. Each scoop delivers 100 calories from non-GMO dextrose (glucose) and cane sugar, along with 310mg of sodium and a blend of potassium, magnesium, and calcium.
The formula uses simple sugars that absorb quickly, providing immediate energy without requiring digestion. This matters during high-intensity efforts when blood flow is diverted away from your gut to working muscles. Tailwind’s approach means you don’t need to carry gels, chews, or bars—just mix 2-3 scoops in 18-24 oz of water and you’re set.
Ultra-running legend Courtney Dauwalter has been using Tailwind since 2017, when she first tried it during Run Rabbit Run 100. “I remember loving the taste and how easy it was to get in all the calories I needed,” she shared in a recent interview with the brand. Dauwalter even collaborated with Tailwind to create a limited-edition Dauwaltermelon flavor, combining watermelon and lime for a refreshing taste during summer races.
For athletes tackling extremely long efforts—think 100-mile ultras or multi-day bikepacking trips—Tailwind also offers High Carb Fuel. This newer product is designed for situations where you can’t consume enough calories from real food to maintain performance.
In February 2026, Tailwind launched “Fuel (Your) Further,” a community-powered campaign supporting everyday athletes pursuing personal endurance goals. The initiative offers three winners cash support, gear, and six months of products including Endurance Fuel, High Carb Fuel, Rapid Hydration, and Recovery Mix. Beyond elite athletes like Dauwalter and World Champion cyclist Christopher Blevins, Tailwind is expanding its reach to recreational endurance enthusiasts.
Skratch: Real Food Philosophy and Separate Strategies
Skratch Labs takes a different path. Founded by exercise physiologist Dr. Allen Lim, the brand emphasizes real-food ingredients and matching your nutrition to what you actually lose in sweat. Their Hydration Sport Drink Mix contains 80 calories and 400mg of sodium per serving, with carbohydrates from cane sugar and dextrose—plus real fruit for flavor.
The key difference? Skratch views hydration and fueling as separate needs. Their Sport Drink Mix is formulated primarily for electrolyte replacement and fluid absorption, with just enough carbohydrate (19-20g) to facilitate sodium-glucose co-transport. This process helps water and electrolytes move from your gut into your bloodstream more quickly.
For athletes needing more calories, Skratch developed Super High-Carb Sport Drink Mix. Each 500ml serving provides 100g of carbohydrates—92g from Cluster Dextrin and 8g from fructose—plus 400mg of sodium. The formula delivers 400 calories at an extremely low osmolality of 150 mOsmol/kg, significantly lower than blood (280-290 mOsmol/kg). This matters because lower osmolality means less risk of gastrointestinal distress.
Cluster Dextrin is a highly branched cyclic carbohydrate that’s extraordinarily soluble but digests steadily, similar to real food. Dr. Lim worked for nearly two years with elite athletes, including Olympic Gold Medalist triathlete Gwen Jorgensen and the EF Education First Pro Cycling Team, to prove the science matched real-world practice. The consensus? Super High-Carb is the best liquid carbohydrate source available for those who push so hard they can’t take in enough calories from real food.
Skratch’s connection to professional cycling runs deep—Dr. Lim previously coached Tour de France teams and developed the brand’s products based on the specific needs of world-class cyclists.
Breaking Down the Nutrition
Both brands share common ground: non-GMO ingredients, gluten-free formulas, and no artificial sweeteners. But their nutritional profiles reveal important differences.
Tailwind Endurance Fuel (per scoop):
- Calories: 100
- Carbohydrates: 25g (from dextrose and cane sugar)
- Sodium: 310mg
- Other electrolytes: Potassium, magnesium, calcium (amounts not specified)
- Mix ratio: 1 scoop per 10-12 oz water
Skratch Hydration Sport Drink Mix (per serving):
- Calories: 80
- Carbohydrates: 19-20g (from cane sugar and dextrose)
- Sodium: 400mg
- Other electrolytes: 80mg potassium, 100mg calcium, 80mg magnesium
- Mix ratio: 1 scoop/packet per 12-16 oz water
Skratch provides more sodium per serving—400mg versus Tailwind’s 310mg. This aligns with Skratch’s philosophy of matching average sweat loss. However, Tailwind delivers more calories and carbohydrates in a similar volume of fluid, supporting its all-in-one approach.
Both use a combination of glucose and sucrose (cane sugar) for quick absorption. Tailwind also includes citric acid and sea salt, while Skratch uses real fruit powders and juices for flavoring. This gives Skratch products a more subtle, natural taste that some athletes find easier to drink mile after mile.
For gut-friendliness, both brands perform well. Tailwind’s simple sugar blend absorbs rapidly without requiring complex digestion. Skratch’s lower osmolality formulas minimize the risk of water being pulled into the gut, reducing bloating and nausea.
Hot Weather vs. Cold Weather Considerations
Your fueling strategy may need to shift with temperature. On hot days, you lose more fluid through sweat but burn the same number of calories. This favors Skratch’s approach: use their Hydration Sport Mix at a rate matching your fluid losses, potentially supplementing with Super High-Carb or solid food for additional calories.
In colder conditions, you may not sweat as much but still burn significant energy. Here, Tailwind’s calorie-dense Endurance Fuel shines—you can meet your energy needs without consuming excessive fluid.
Some athletes mix strategies based on conditions. You might carry one bottle of Skratch Hydration for fluid replacement and another with Tailwind or Skratch Super High-Carb for calories. Just be mindful of the math: too many carbohydrates consumed too quickly can cause GI distress regardless of the brand.
Which One Should You Choose?
Your ideal choice depends on several factors:
Choose Tailwind Endurance Fuel if:
- You prefer a single-bottle solution for hydration, electrolytes, and calories
- You’re running or cycling at moderate intensity for 2-6 hours
- You struggle with solid food during exercise
- You want higher calorie density per bottle
Choose Skratch Hydration Sport Drink Mix if:
- You prefer separating hydration from fueling
- You’re comfortable eating real food or gels for calories
- You prioritize a subtle, real-fruit taste
- You train in hot conditions and need maximum fluid replacement
- You want precise electrolyte matching based on sweat science
Consider Skratch Super High-Carb if:
- You’re tackling ultra-distance events (100+ miles)
- You can’t consume enough real food to maintain performance
- You need 60-100+ grams of carbohydrates per hour
- You’ve experienced GI issues with traditional maltodextrin-based products
Both brands have earned their reputations through athlete testing and transparent ingredient lists. Tailwind powers ultra-runners like Courtney Dauwalter through 100-mile races, while Skratch fuels World Cup cyclists and Olympic triathletes through multi-hour efforts.
The best approach? Test both in training before race day. Start with shorter efforts to gauge taste preferences and stomach tolerance. Pay attention to how you feel at mile 15 versus mile 3—that’s when nutrition differences become most apparent.
Find Your Formula
Endurance nutrition isn’t one-size-fits-all. Tailwind’s all-in-one simplicity appeals to minimalists who want everything in one bottle. Skratch’s real-food philosophy and separate hydration/fueling strategy resonates with athletes who treat nutrition like a science experiment, adjusting each variable based on conditions.
Both brands deliver clean, effective products backed by real-world testing from elite athletes. The right choice comes down to your specific training demands, taste preferences, and how your gut responds during long efforts.
Start experimenting now, well before your goal race. Your stomach will thank you at mile 20.